BEARING STEEL EXCELLENT IN DELAYING PROPERTY IN CHANGE OF MICROSTRUCTURE CAUSED BY REPEATED STRESS LOAD AND HEAT TREATING PRODUCTIVITY

摘要

PURPOSE: To produce bearing steel small in the change of the microstructure caused by repeated stress loads under severe using conditions and high in heat treating productivity. ;CONSTITUTION: The bearing steel contg., by weight, 0.001 to 0.015% Sb for improving heat treating productivity and contg., particularly, 2.0 to 5.0% Mn and one or ≥two kinds selected from 0.5 to 2.5% Si, 2.5 to 8.0% Cr, 1.0 to 3.0% Ni, 0.5 to 2.0% Mo, 0.012 to 0.050% N, 0.05 to 1.0% V, 0.05 to 1.0% Nb, 0.05 to 1.0% W, 0.02 to 0.5% Zr, 0.02 to 0.5% Ta, 0.02 to 0.5% Hf and 0.05 to 1.5% Co as B₅₀ high load rolling fatigue life improving components for prmoting the delay in the change of the microstructure caused by repeated stress loads and in which the maximum grain size of oxide non-metallic inclusions is regulated to ≤8μm is produced.;COPYRIGHT: (C)1994,JPO